In the formation of integrated circuits, transistors are often formed in well regions, which include p-well regions and n-well regions. The well regions are typically applied with bias voltages, or electrically grounded. In order to apply the bias voltages, pickup regions and the respective contact plugs are formed to connect to the well region. The pickup regions are heavily doped semiconductor regions at the surfaces of the well regions. A p-well region has a heavily doped p-type pickup region, and an n-well region has a heavily doped n-type pickup region.